Demand in ERCOT

Nodal Demand

Description

Demand is modeled at the substation (node) level with hourly resolution to capture both intraday shape and seasonal effects. The primary input is ERCOT’s Long-Term Load Forecast (LTLF), which provides weather-zone hourly profiles through 2045 and separates demand into:

• Base (economic) load
• Behind-the-meter (BTM) rooftop PV
• Electric vehicles (EVs)
• Oil and gas demand
• Large loads (data centers)

The base, PV, EV, and large flexible load (LFL) categories are taken from the LTLF. ERCOT’s Contracts & Officer Letters are not used for large loads. Instead, Modo Energy’s in-house large load forecast is applied, described below. Oil & gas electrification assumptions are anchored to ERCOT’s Permian Basin Reliability Planning Study.

Base load and EV shapes are weather dependent, so each month of the forecast is served from the LTLF profile of the historical year that represents that month in the synthetic weather year. See the Generation page for the month-to-year mapping.

Large loads

The large load forecast combines a bottom-up catalogue of named projects with a top-down view of total data center demand.

• Bottom-up: Modo Energy maintains a catalogue of data center projects drawn from ERCOT’s large load interconnection queue, PUCT filings and company announcements. Projects with an assessed likelihood of at least 50% are included. Each project’s nameplate request is converted to a peak grid draw using a peak utilization factor, the share of the site expected to be served from the grid, and a coincidence factor at the system peak. On-site generation is netted off where it has been announced.
• Ramp: Projects ramp to their full grid draw over five years from their energization date, following ERCOT’s phased approach to allocating load to new large load interconnections.
• Top-down: Modo Energy also estimates the total data center contribution to ERCOT’s coincident peak load by weather zone. Where the named projects fall short of this total in a year, the residual is placed on transmission stations that carry large load requests in ERCOT’s planning cases.
• Siting: Projects are connected to the transmission bus nearest their site.

Oil and gas loads in the Permian Basin are tracked separately and added on top of the data center forecast.

Load assumptions

Load assumptions across the Central Scenario, High Gas Buildout, Low Gas Buildout, and High Zero-Carbon Buildout scenarios remain consistent. The High Demand Growth scenario applies a higher top-down target for data center contribution to peak, roughly 40 GW by 2033 against 28 GW in the Central Scenario, together with higher peak utilization and coincidence factors.

Load profiles

Each load component exhibits a different profile based on function, price responsiveness and any on-site behind-the-meter generation.

Assumptions and Caveats

• From 2034, demand growth is applied at the weather zone level, without explicit nodal detail.
• Data center load is shown before on-site generation in the charts above. On-site generation is netted off in the model.

Data Sources